"There are several stages in the development of human
knowledge, which are repeated in all small (and even
smaller) components, in the directions we discover, in
problems and questions we ask and try to solve.
First, we are just curious . At this stage we
ask natural questions (which are not necessary "good"
questions). However, these ``natural" questions force us
to start to think about the subject; they slowly prepare
us for the next stage.
We then begin to think about the subject and our
questions become much less ``natural", they become deeper
and less predictable, and the answers we accumulate begin
to piece together a puzzle. But the picture is not yet
complete.
The next stage is understanding , and later on
there is knowing . Only at the end, do we finally possess our knowledge: we may use it, we may apply
it, but, in fact, more than that, we possess it."

The pictures above represent:
The Past: "a la" (typical) Fayum portrait (which shows
a person from about 2.000 years ago).
The Present: a (hopefully typical) modern person. As in
almost any portrait of the last 500 years, we clearly
recognize "the stage of thinking", and not just
"curiousity".
The Future: this is the only portrait I found (of course,
of Leonardo) which reflect not only "thinking" but already
an "understanding". It gives us the hope that we are
getting "there", to that stage.